1. Field of the Invention
The present invention relates to an environment recognizing device for a vehicle, and a vehicle control system using the same. For instance, the present invention relates to an environment recognizing device for a vehicle that detects a vehicle or a pedestrian in front of the own vehicle on the basis of image information from a vehicle-mounted camera (imaging device), and a vehicle control system using the same.
2. Background Art
To reduce the toll of casualties due to traffic accidents, preventive safety systems for preventing accidents have been developed. The preventive safety systems operate under situations with a high possibility of causing accidents. For instance, a pre-crash safety system and the like have been put into practical use. For instance, this system warns a driver with an alarm when a possibility of collision with a preceding vehicle in front of the own vehicle occurs. In a situation where a collision is unavoidable, this system reduces damage to an occupant by automatically braking.
As a method of detecting a preceding vehicle in front of the own vehicle, a method has been known that takes an image in front of the own vehicle by a camera, and detects a shape pattern of the vehicle from the taken image according to a pattern matching process. The pattern matching process typically has a high processing load. Thus, in order to reduce the processing load, it is typical to perform edge analysis before the pattern matching process, narrow down a region in which a vehicle is likely to exist, and then perform the pattern matching process. For instance, JP Patent Publication (Kokai) No. 2006-182086 A (2006) describes a method that detects a vehicle candidate from an edge of an image, and determines that the object is a preceding vehicle according to a pattern matching.
Meanwhile, as another method of detecting a preceding vehicle in front of the own vehicle, a method has been known that extracts red regions characterizing the taillights of the preceding vehicle, and detects the vehicle using the red pair. For instance, JP Patent Publication (Kokai) No. 2006-244331 A (2006) discloses a method that extracts a luminance signal having at least a prescribed threshold from an image, and detects the taillights of the preceding vehicle from positional relationship and the like.
In the above techniques for detecting a vehicle, the former has an object to control an alarm, brake and the like. Accordingly, erroneous detections in scenes without risk of collision in actuality are required to be reduced as much as possible. The latter has an object to automatically adjust an own vehicle's lighting device in order to improve visibility of the own vehicle in the night. Accordingly, the latter has erroneous detections more than the former.